The present innovation regards a cover for the case of the reduction unit of a motor reducer. The innovation further regards a motor reducer, the case of the reduction unit of which comprises the said cover.
As is known, a motor reducer in general comprises a casing, which contains inside it the electrical parts making up the electric motor, and a case for containing the gears that make up the speed-reduction unit. Normally, the electric motor assembly is fixed to the reduction unit by means of screws or similar mechanical elements.
In addition to containing, as has already been said, the reducing gears and the possible corresponding gear shafts, the case of a reduction unit also comprises a certain amount of lubricating oil which, in the traditional manner, facilitates sliding of the gear teeth over one another during meshing. For this reason, such a case of the reduction unit is in general provided with an opening through which lubricating oil is injected into the inside. With this opening, which is obviously set on the top of the case, a plug is associated, which is provided with a through hole as breather hole, by means of which it is possible to expel both the air that is present inside the case and the vapours that form, above all, on account of the heating and shaking to which the lubricating oil is subjected. By means of the aforesaid breather hole, it is thus possible to eliminate the overpressures that would form inside the case if there were not a passage leading out both for the air and for the vapours.
A solution adopted in some motor reducers known to the state of the art consists in making on the walls of the case a series of openings, each of which provided with a corresponding plug for closing, designed, according to the needs and the spatial positioning of the motor reducer, to provide a top opening for charging with lubricating oil and as a breather hole, a bottom opening for draining off the said oil, and an intermediate opening for reading the oil level. In other words, for each spatial position of the motor reducer, it will be necessary to choose a set of three openings, each provided with its own plug, consisting of a first, top, opening to be used for charging with lubricating oil and as a breather hole, a second, bottom, opening designed for discharging the used lubricating oil, and a third, intermediate, opening used for checking the oil level inside the case.
It is evident that, in order to guarantee breather operation, the closing plug combined with the top opening for oil filling must be provided with a through hole for breathing.
In another embodiment of the prior art there is no need for the openings to be provided for discharging the oil and the openings for checking maintenance of the oil level, because the case is filled, once and for all, with the lubricating oil that is to be used for the entire service life of the motor reducer. In this latter case, no opening may be provided. It is, however, advisable, even for this type of lubrication, to provide a through breather hole of the type previously described, so as to reduce overpressures inside the case.
From what has been said, it immediately emerges that in the traditional solutions the reduction-unit case must be provided with a large number of openings, each equipped with its own plug for closing, these openings being designed to work, as the need may be, as opening for oil filling, for discharging, or for checking oil level, according to the spatial position occupied by the motor reducer, a spatial position which ultimately depends upon the position of the mechanical device to which the motor reducer is to be coupled and upon the space available. It is likewise evident that, after the motor reducer has been fixed in its final position of use, only the plug set in the highest position will need to be provided with a through hole for expulsion of the air and vapours.
The purpose of the present innovation is thus to simplify the construction of cases for motor reducers considerably by eliminating the need to provide a large number of holes on the case and to associate to each hole a corresponding plug.
According to the present innovation, a cover is therefore made, equipped for the case of a reduction unit of a motor reducer, the said case being designed to contain the reducing gears; cover characterized in that it is provided with a first opening with which is combined a corresponding plug, the said plug being provided with a through hole as breather hole for the air and vapours that develop on account of the heating and shaking of the lubrication oil contained in the case.
A further subject of the present innovation is a motor reducer equipped with the said cover.